Loop-type impedance relay or the like



Juli 10, 1945- s. L.. GoLDsBoRoUGH l 2,380,164k

LOOP-TYPE IMPEDANCE-RELAY OR THE- LIKE Filed Sept. 22, 1945 ATTOR NEY Patented July 10, 1945 LOOP-TYPE IMPEDANCE` RELAY OR THE LIKE Shirley L. Goldsborough, Baskng Ridge, N. J., as-

signor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsyl- Vania Application September 22, 1943, Serial No. 503,367

(Cl. 17E-294) 11 Claims.

My present invention relates to improvements in distance-measuring relays, and it provides a basis for a universal high-speed relay-element which, by proper control of the design-constants, can be made to perform any relayfunction, such as impedance, reactance, resistance, directional, differential, or overcurrent relays, and other types of relays.

A particular object of my invention is to provide a distance-measuring effect, or in general, any Idiferential comparison of any two electrical quantities, one against the other, in a wattmetricor directional-type relay, and particularly in a loop-type relay which eifects a multiplication of two electrical quantities.

Heretofore, distance-type relay-elements have been constructed so that opposing forces are applied to a beam, pivoted at its center. There are certain disadvantages which have been experienced with this type of construction, which has been in standard use for a good many years. The beam-type relay has been subject to change in calibration, because of slight changes in the initial or reset position of the beam. At the balance-point, heavy forces are mechanically balanced against each other through a bearing. The beam-type element `does not lend itself well to perform other functions, such as directional responses, reactance-responses, and many others.

It is a particular object of my invention to accomplish the functions which were formerly obtained on a balanced beam, by now using a process of multiplication, in a directional element, wherein the polarized coil may be energized, for example, lwith the quantity (E-i-I), and the fieldcoil may be energized, for example, with the quantity (E-I) The action of a directional element is to multiply its polarizing and held-coil quantities, obtaining a force which is proportional, for example, to (E--I) (E-I). By a proper control of the desi-gn-constants of the E and I quantities in both terms, I can make the relay respond to E2-I2=0, which is an impedance-response, or by proper change in the constants, practically all other kinds of relay-responses may be obtained.

With the foregoing and other objects in View, my invention consists in the apparatus, combinations, systems, parts and methods hereinafter described and claimed, and illustrated, in the accompanying drawing, wherein:

Figure l is a diagrammatic plan-view of a loop-type distance-relay of my invention, shown with the loop in section,

Fig. 2 is a vector'diagram which will be referred to in the explanation, and

Fig. 3 is a diagrammatic view of circuits and apparatus illustrating a different form of embodiment of the invention.

My present invention may be applied to any kind of directional or product-responsive relay. I have illustrated it, and I at present prefer to use it, however, in connection with a directional relay of the loop-type, in which the movable element is simply a loop or a plurality of loops, which may be extremely light in weight, for any given torque, resulting in a small, lightweight relay having a high speed of action. Where such qualities, particularly the high speed of opera-` tion, are not desired, the invention may be applied to other, slower-acting types of directional or wattmetric relays,

The basic design of the relay-structure may be the same as, or improvements on, any known form of loop-type relay, such as that which is shown in a Patent 2,300,866 of Bert V. Hoard and myself, granted November 3, 1942, or in any one of three copending applications of myself and others, Serial Nos. 503,366, 504,696, and 516,238, filed September 22, 1943, October 2, 1943, and December 30, 1943, respectively.

In Fig. 1, I have illustrated my invention in lthe form of va relay-element which is structurally like that which is shown in my aforesaid Patent No, 2,300,866. It may be either a single-phase or a polyphase' element. I have illustrated it as a single-phase element or unit, in Fig. 1 of the accompanying drawing, wherein a closed ring 4 of laminated magnetic material is provided, having a reentrant portion or pole-piece 5 which extends, from the back side 6 of the relay-frame 4, toward the front side 1 thereof, being spaced from the front arm or leg 'l of the relay, by an airgap S. The front arm or leg 'l of the relayframe is threaded through the hole of a loop ID, which is pivoted, off to one side, at a pivot-point i l, so that the loop is free to swing, and to move back and forth for a short distance along the front Yleg l, withoutftouching the same, so that a coil-side I2 of the loop may be within the airgap 8.

This type of element has two magnetic circuits, which are traversed by two different alternatingcurrent uxes. One of these fluxes flows through the central leg or pole-piece 5 and across the airgap 8, and then divides, half of said flux returning through each of the side-legs I3 and I4 of the field-frame 4. The other magnetic flux circulates back and forth around the outer ring or yoke of the magnetic frame 4, for instance moving forwardly along the side-arm I4, to the left across the front arm 1, back along the other side-arm I3, and to the right along the back arm 6, to its starting-point.

According to my present invention, both current-excitation and voltage-excitation are utilized for one or both of these two magnetic circuits of the relay. In the general case, as illustrated in Fig. l, currentand voltage-responsive excitation is utilized on both of the magnetic circuits. Thus the central leg or pole-piece 5 is provided with both a voltage-coil I5 and a current-coil I6, energizing one of the magnetic circuits. In like manner, the two outer legs I3 and I4 are each provided with a voltage-coil I1 and a currentcoil I8, to energize the other magnetic circuit of the relay. The three voltage-coils I5, I'I are shown as being connected in series with each other, and energized with a voltage-responsive exciting-current mE, although other forms of energization may be utilized. The three currentcoils I6, I8 are in like manner illustrated as being connected together in series and energized with a current-responsive exciting-current nl. The polari'ties of the coils are such that the outer legs, or the loop-circuit of the magnetic frame-member 4, are excited in accordance with a function of (EI-I), while the central leg or pole-piece 5 is energized in response to a function of the quantity (E-I).

The outer-leg flux, which is responsive to (E+I) in Fig. 1, induces a current in the loop I0, and this current, flowing in the loop-side I2, reacts with the airgap-flux which is responsive to (E-I), to I' T= K1E+K2I (Kw-Kd) (l) where K1, K2, K3 and K4 are design-constants. If 9 is the angle between E and I, this producttorque may be multiplied out to obtain If We make K1=K3 and K2=K4, the cosine terms cancel out, and we have a torque which is responsive to K12E2-K22I2- At the balance point of the relay, this torque is zero, and we have which is a response to the apparent or measured line-impedance .Z=E /I If we had omitted, altogether, the voltage-coil I5 on the central leg 5 of the relay, in Fig. 1, making `LK3=0, and if we had introduced a 90 phase-shifter so that the phase-angle between E and I is (0A-90) instead of 0, We would have obtained a balance-point of the relay at which is a response to the apparent or measured line-reactance X.

Any sort of compromise-characteristic, between impedance, reactance, or resistance, can be obtained, as can be seen from Equation 2, by the y proper selection of the K constants, so that the cosine terms do not cancel out entirely. Or, by putting only a voltage-response on one magnetic circuit, and only a current-response on the other,

`as by making K2=K3:0, we may obtain a Conventional directional response, KlKrEI cos 0, or by introducing any phase-angle S by means of a phase-shifter, we can make the response KiKiEI cos (H4-S).

In general, any values at all may be assigned to the constants K1, K2, Ks and K4, and any phase-angle relationship may be maintained between E and I. Also a different pair of E and l', with different phase-angle relationships, may be utilized on the two different magnetic circuits of the relay, as explained, for example, in my copending application, Serial No. 504,695, filed October 2, 1943. In other Words, I have provided a .conventional product-responsive relay, which is essentially a directional or wattmetric ele ment, and by proper choice of constants I have been enabled to obtain a response to the difierence between two electrical quantities, either independently of 'the phase-angles between those quantities, or with any variation between a nondirectional inference-response and a full-directional or Wattmetric response.

Fig. 2 shows a vector diagram which brings out pictorially the action which takes place in a directional element in which the constants are chosen so that the element operates as an impedance-element. The current vector I is made equal to the voltage vector E, lagging behind it by any angle 9. The polarizing coil, for instance, receives (E-I-I) and the field-coil (E-I). These quantities are shown in Fig. 2. An inspection of Fig. 2 reveals that the angle B between the (E4-I) quantity and the (E-I) quantity is given by In other words, the angle between the two quantities which the relay multiplies is always 90, regardless of the phase-angle 0 between E and I.

vIf the relay is designated to have a true wattcharacteristic, so that it responds to the product of its two magnetizing forces times the cosine of the angle B between them, the relay will have a zero torque, and Fig. 2 will represent the balancepoint of the relay, regardless of the values of the angle 0 between E and I.

For a fault which is closer to the relay than the conditions depicted in Fig. 2, the E-vector will be shorter, and it can be seen that this will cause the angle B to become greater than 90, which will produce a torque to close the contacts of the relay. A fault which is beyond the balancepoint depicted in Fig. 2 will cause B to become less than 90", producing a contact-opening torque.

This principle of operation is quite general, and it can be applied to any directional orwattmetric relay-element, in which the torque is the product of two electrical quantities, whether a current and voltage, or two currents, or any other combination of two different electrical quantities of a given frequency. In particular, in accordance with my present invention, I am enabled to apply it to a high-speed loop-type product-element, in order to obtain a distance-responsive relay which can perform all of the functions which may be required of any distance-relay, or modified-distance or reactance-relay, etc., by merely changing the coil-constants. s

In Fig. 3, I illustrate certain ways in which the construction and control may be varied. For example, instead of utilizing a current-coil and a voltage-coil on each magnetic circuit of the relay, and applying separate current-responsive and voltage-responsive. excitations to the two coils, I can utilizea three-winding transformer 29 for combining the voltage and current-responses to obtain a secondary current Is which is proportional to the sum (E-l-I), and another three-winding transformer 30 for producing a secondary current ID which is proportional to the difference (E-I), as described in my aforesaid copending application Serial No. 504,695. Each of these three-winding transformers 29 and 3l) may have a voltage-responsive primary winding 3|, a current-responsive primary winding 32 and a secondary winding 33, the voltage-responsive winding being excited through an impedance 34 which is large in comparison to the magnetizing impedance of said Winding, so as not to interfere with the flux-changes'in the transformerion due to the current coil 32.

In Fig. 3, I have also illustrated the fact that two loop-torque responses may be utilized, having the double-frequency, pulsating components of their torques eXactly equal and opposite to each other, so that the resultant torque is a constant steady or non-pulsatory torque, for any given magnitude of E and I and for any given value of the phase-angle between them. To this end, 'I have illustrated, in Fig. 3, a form of relay-construction which is described and claimed in my aforesaid copending application Serial No. 516,238, in which two loops A and B are utilized, disposed at right angles to each other, or in space-quadrature relation, and having their several loop-sides 4|, 42, 43 and 44 disposed in air gaps under four poles 52, 53 and 54, of a laminated magnetizable frame or yoke 55.

One of the magnetic fluxes, which I have designated en, passes in a straight line diametrically across the instrument or through points 180 electrical degrees apart, through the poles 5| and 53, under the excitation of coils 6| and 63 which `are excited with the difference-current n=(E-I), as supplied by Athe three-winding transformer 30. The other magnetic flux, marked es, extends diametrically across the instrument, through the other poles 52 and 54, which are excited by coils 62 and 64 which are energized with the sum-current Is=(E-l-I), which is supplied by the other three-winding transformer 29. The magnetic circuit, inside of the loops A and B, may be completed, either in air, or preferably through a magnetizable member 65, which I have illustrated diagrammatically as a stationary member which is supported from suitable insulating supporting-pieces 66 and 61.

The result of the relay-structure shown in Fig. 3 is that theloop A is excited with a loop-current which is induced by the summation-flux cs, and this loop-current reacts with the differential ux D to produce a clockwise torque TA. The current in the loop B is induced by the difi'erential flux qm, and it reacts with the summation-flux ps in the airgaps under the poles 52 and 54, producing a counterclockwise torque TB. It can be readily shown that the double-frequency pulsating components of these two torques TA and TB exactly cancel each other, when the torques are added algebraically, so that the total resultant torque of the relay is a steady quantity, lacking the double-frequency torque-pulsations Which are the characteristic of all singletorque, single-phase product-responsive relays, as well as simple beam-type relays.

The broad concept of a wattmeter-type device in which one of the fluxes which are multiplied is a flux having a current-responsive component and a Voltage-responsive component is described and claimed in an application of Bert V. I-Ioard, Serial No. 456,901, led September 1, 1942, and assigned to the Westinghouse Electric & Manufacturing Company.

While I have illustrated my invention in .certain particular structural forms, and while I have described its general principles of operation, as well as certain specic choices of the various design-constants, I wish it to be understood that I am not limited to the precise structures, circuits, combinations, or choices of relative designconstants which I have chosen for illustration. I desire, therefore, that the appended claims shall be accorded the broadest construction consistent with their language and the prior art.

I claim as my invention:

1. A substantially non-vibratory, product-responsive, single-phase, torque-producing relayelement adapted for use on an alternating-current system and comprising a stator member and a rotor member, one of said members comprising four successive windings of an electrically excited magnetizable element, the other of said members comprising two mechanically connected loopsv A and B, rstand third-winding exciting-means of said electrically excited magnetizable element for causing one alternating flux to enter at one loop-side of loop A and leave at the other loopside of loop A, interlinking through loop B in the process, and secondand fourth-winding exciting-means of said electrically excited magnetizable element for causing another alternating flux to enter at one loopside of loop B and leave at the other loop-side of loop B, interlinking through loop A in the process, the exciting-means which produces at least one of said iluxes being responsive to the vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-voltage.

2t A substantially non-vibratory, productresponsive, single-phase, torque-producing relayelement adapted for use on an alternating-current system and comprising a stator member and a rotor member, one of said members comprising four successive windings of an electrically excited magnetizable element, the other of said members comprising two mechanically connected loops A and B, i'lrstand third-winding excitingmeans of said electrically excited magnetizable element for causing one alternating fiux to enter at one loop-side :of loop A and leave at the other loop-side of loop A, interlinking through loop B in the process, and secondand fourth-winding exciting-means of said electrically excited magnetizable element for causing another alternating flux to enter at one loop-side of loop B and leave at the other loop-side of loop B, interlinking through loop A in the process, the exciting-means which produces one of said fluxes being responsive to the vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-voltage, and the exciting-means which produces the other flux being responsive `to a different vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-voltage,

43. A substantially non-vibratory, productresponsive, single-phase, torque-producing relayelement adapted for use on analternating-current system and comprising a stator member and a rotor member, one of said members comprising an electrically excited magnetizable element having four exciting-winding means symmetrically disposed in two pairs of diametrically opposite means, the other of said members comprising two mechanically connected loops Aand B disposed at substantially right angles to each other andhaving their four loop-.sides disposed near the center-lines of the respective excitingwinding means of the electrically excited magnetizable members, and two supply-circuit means for the respective pairs of diametrically opposite means, whereby two uxes are caused to iiow diametrically across the relay-element, in the two diameters, at least one of said `supply-circuit means being responsive to the vectorial ,sum of an alternating-current function of a line-currentl and an alternating-current,function of a line-voltage.

4. A substantially non-vibratory, product-responsive, single-phase, torque-producing relayelement adapted for use on an alternating-current system andcomprising a stator member and a rotor member, one of said members comprising an electrically excited magnetizable element having four exciting-winding means symmetrically disposed in two pairs of diametrically opposite means, the other of said members comprising two mechanically connected loops A and B disposed at substantially right angles to each `other .andihaving their four loop-sides disposed near the center-lines of the respective excitingwinding means of the electrically excited magnetizable members, and two supply-circuit means for the respective pairs of' diametrically opposite means, whereby two fluxes are caused to flow diametrically across the relay-element, in two diameters, one of said supply-circuit means being responsive to the vectorial sum of an alternatingcurrent function of a line-current and an alterhating-current function :of a line-voltage, and the other supply-circuit means being responsive to a different vectorial sum of an alternating-current function of a line-current and an alternatingcurrent functionof a line-voltage.

5. A substantially non-vibratory single-phase Atorque-.producing electro-responsive device adapted for use on an alternating-current system and comprising ,a movable member having `a rotormember comprising two symmetrically disposed loops'at substantially right angles to each other, Vwith one loop inside of the other, a magnetizable field-member having four salient poles coinciding with the respective loop-sides, an exciting-coil means on eachpole, and two `different energizingmeans whereby two .diametrically oppositepoles carry `one alternating flux and the other two .diametrically-opposite poles carry .another alternating `flux, at least one of said energizing-means being responsive to the vectorial sum of `an ialterhating-current function of a line-current .and an kalternating-current function of a line-voltage.

6, A substantially non-vibratory` single-phase torque producing electro responsive vdevice adapted for use on an alternating-current,system and comprising a movable member-having a rotor-member comprising two symmetrically disposed loopslatsubstantially right angles to each other, with oneloop insideof the other, a magnetizable'field-member having four salient poles coinciding with the respective loop-sides, an exciting-,coil means on each pole, and two different energizing-means kwherebytwo diametrically opposite poles carry one alternating ilux and the other two diametrically opposite poles carry another alternating iiux, one of said energizingmeans being responsive to the vectorial sum of an alternating-currentfunction of a line-current and an alternating-current function of a linevoltage, and the other-energizing-means being responsive to a different .vectorial sum of an alterhating-current function of a line-current, and an alternating-current function of a line-voltage.

7. A substantially non-vibratory single-phase torque-producing electro-responsive device comprising a movable member having a'rotor-member comprising two ysymmetrically disposed loops at substantially right angles to each other, with one loop `inside'of the other, a magnetizable fieldmember having four salient poles coinciding with the respective loop-sides, an exciting-coil means on each pole, and two different energizing-means whereby two diametrically opposite poles carry one alternating flux and the other two diametrically opposite poles carry another alternating flux, one of said energizing-means being responsive to (E-l-I) andthe other being responsive to (EI), where E and I represent any two alternating fluxproducing forces, each compounded of aconstant times-a single-phase exciting-current, the two exciting-currents being relatively variable, both as to phase and magnitude, with respectto each other.

8. A substantially non-vibratory, product-responsive, single-phase, torque-producing relayelement adapted for use on an alternating-current system and comprising a stator member and a rotor-member, one of said members comprising four successive windings of an electrically excited magnetizable element, and four winding-exciting means for said four successive windings, the firstand third-winding exciting-means producing one alternating iiux, the secondand fourth-winding exciting-means producing a space-quadrature-related alternating flux, the other of said members comprising a conducting secondary member traversed by said two space-quadrature-related alternatingfluxes and so disposed that each nux enters and leaves the conducting secondary member atpoints approximately electrical degrees apart and thereby induces a circulating secondary current which llows in a path or paths having a torque-producing relation with the other flux, each flux interlinking through the path or paths ofthe` circulating secondary current which it inducesythe exciting-means which produces one of said `fluxes `being responsive to the vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-voltage, and the exciting-means which produces the other ux being responsive to a different vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-Voltage.

`9. A substantially non-vibratory, product-responsive, single-phase, torque-producing relayelement adapted for use on an alternating-current system and comprising a stator member and a rotor member, one of said members comprising an electrically excited magnetizable element having four exciting-winding means symmetrically disposed in `two pairs of diametrcally opposite means, and two supply-circuit means for the respective pairs of diametrically opposite means, whereby two iiuxes are caused to flow diametrically across the relay-element, in the two diameters, the other of said members comprising a conducting secondary member traversed by said two uxes and so disposed that each flux enters and leaves the conducting secondary member at approximately diametrically opposite points and thereby induces a circulating secondary current which flows in a path or paths having a torqueproducing relation with the other flux, each iiux interlinking through the path or paths of the circulating secondary current which it induces, one of said supply-circuit means being responsive to the vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-voltage, and the other supplycircuit means being responsive to a different vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-voltage.

10. A substantially non-vibratory single-phase torque producing electro responsive device adapted for use on an alternating-current system and comprising a movable member having a conducting secondary rotor-member, a magnetizable held-member having four salient poles approximately uniformly spaced around said rotor-member, an exciting-coil means on each pole, and two different energizing-means whereby two diametrically opposite poles carry one alternating flux and the other two diametrically opposite poles carry another alternating ux, said conducting secondary rotor-member being traversed by said two uxes and so disposed that each ux enters and leaves the conducting secondary rotor-member at approximately diametrically opposite points and thereby induces a circulating secondary current which flows in a path or paths having a torque-producing relation with the other flux, each flux interlinking through the path or paths of the circulating secondary current which it induces, one of said energizing-means being responsive to the vectorial sum of an alternatingcurrent function of a line-current and an alternating-current function of a line-voltage, and the other energizing-means being responsive to a different vectorial sum of an alternating-current function of a line-current and an alternating-current function of a line-voltage.

1l. A substantially non-vibratory single-phase torque-producing electro-responsive device cornprising a movable member having a conducting secondary rotor-member, a magnetizable eldmember having four salient poles approximately uniformly spaced around said rotor-member, an exciting-coil means on each pole, and two different energizing-means whereby two diametrically opposite poles carry one alternating flux and the other two diametrically opposite poles carry another alternating flux, said conducting secondary rotor-member being traversed by said two fluxes and so disposed that each ux enters and leaves the conducting secondary rotor-member at approximately diametrically opposite points and thereby induces a circulating secondary current which flows in a path or paths having a torqueproducing relation with the other flux, each iiux interlinking through the path or paths of the circulating secondary current which it induces, one of said energizing-means being responsive to (E-l-I) and the other being responsive to (E-I), where E and I represent any two alternating nuxproducing forces, each compounded of a constant times a single-phase exciting-current, the two ex* citing-currents being relatively variable, both as to phase and magnitude, with respect to each other.

SHIRLEY L. GOLDSBOROUGH. 

